acpi_gpiobus: Use non-rman resource activation

[cperciva]

Summary

bus_generic_activate_resource passes requests up to the parent device
and ultimately ACPI will do what we need for us.

This overrides gpiobus, which uses bus_generic_rman_activate_resource.

Sponsored by: Amazon

[cperciva]

@jhb You switched gpiobus from bus_generic_activate_resource to bus_generic_rman_activate_resource in https://reviews.freebsd.org/D43887 and that wasn't working for my GPIO _AEI driver. I *think* this commit is correct (that ACPI takes care of things for us with an ACPI GPIO device) but I'm not 100% sure.

[jhb]

Eh, this doesn't seem correct on the surface. How are the resources being allocated? If they are being allocated via gpiobus_alloc_resource(), then it is wrong to pass those resources up to some random other device driver in the tree and ask it to activate a resource it didn't create and doesn't know how to manage. Do you have more details on "that wasn't working"? Do you get a panic?

[cperciva]

In D47252#1077458, @jhb wrote:

Eh, this doesn't seem correct on the surface. How are the resources being allocated? If they are being allocated via gpiobus_alloc_resource(), then it is wrong to pass those resources up to some random other device driver in the tree and ask it to activate a resource it didn't create and doesn't know how to manage. Do you have more details on "that wasn't working"? Do you get a panic?

No panic, but bus_setup_intr fails. The IRQ is being initially assigned in gpio_alloc_intr_resource:

res = bus_alloc_resource(consumer_dev, SYS_RES_IRQ, rid, irq, irq, 1,
    alloc_flags);

[andrew]

The issue is we need to call into subr_intr.c to activate the interrupt. Currently this is done in nexus on arm, arm64, and riscv but this requires calling the parent bus_activate_resource in each bus driver.

[jhb]

Presumably the gpiobus driver needs to call into subr_intr.c for those platforms then? (And that needs to happen in gpiobus.c, this is not ACPI specific)

[andrew]

Is there a reason to not do it in bus_generic_rman_activate_resource on those archs? We could then replace nexus_activate_resource with bus_generic_rman_activate_resource on arm and riscv (it's missing non-posted memory support needed on arm64)

[jhb]

Hmmm, if the logic is the same for all IRQ resources ever allocated on intrng architectures, then doing it in the wrapper might indeed be simplest.

[cperciva]

I honestly don't know enough about the resource activation and intrng code to understand the alternative you two are discussing -- can I leave it with you to figure out what needs to be done here in the upcoming week? I'd like to make sure the _AEI support lands in time for 14.2 since it's a major pain point for AWS.

[andrew]

See D47282 for teaching bus_generic_rman_activate_resource about INTRNG

[cperciva]

I have confirmed that D47282 does what is needed here.